Rearrange Array to Maximize Prefix Score
A medium-tier problem at 42% community acceptance, tagged with Array, Greedy, Sorting. Reported in interviews at J.P. Morgan and 1 others.
Rearrange Array to Maximize Prefix Score shows up in real OAs from J.P. Morgan and IBM, and it catches people who jump straight to code without thinking about the order. The problem forces you to choose not just what to include, but in what sequence, which breaks the instinct to process linearly. With 41% acceptance, half the candidates either miss the greedy insight or second-guess themselves under time pressure. If you freeze on this one live, StealthCoder runs invisibly and surfaces the working rearrangement in seconds.
Companies that ask "Rearrange Array to Maximize Prefix Score"
Rearrange Array to Maximize Prefix Score is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoderThe trick is pure greedy: at every step, choose the element that maximizes the current prefix sum, not the final total. Most people think 'just sort descending' and miss that you're building a cumulative score as you go, and staying positive matters. Once a prefix sum drops below zero, it poisons all future scores. The optimal move is always to pick the next element that keeps the running sum as high as possible. The pattern is Sorting and Greedy working together. Prefix Sum tracking tells you when you've hit the wall. StealthCoder catches this pattern instantly if you're stuck on the logic during your live assessment, so you don't burn 15 minutes on a suboptimal approach.
Pattern tags
You know the problem.
Make sure you actually pass it.
Rearrange Array to Maximize Prefix Score recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Rearrange Array to Maximize Prefix Score interview FAQ
Is this really a greedy problem or do I need dynamic programming?+
Pure greedy. DP would solve it but is overkill and TLE-prone. At each step, pick the element that maximizes your current prefix sum, then remove it. The locally optimal choice is globally optimal here. No state table needed.
Why do companies like J.P. Morgan ask this instead of just a sort?+
It tests whether you understand prefix sums and can reason about constraints in real time. Sorting alone is mechanical. This asks if you can reframe a greedy problem and defend your choice under pressure.
What's the most common mistake?+
Sorting the array once and calling it done. Candidates forget that the score is cumulative and order matters per-step. They also don't realize that once a prefix sum goes negative, you need a strategy to recover or prevent it.
How does this relate to prefix sum problems in general?+
Standard prefix sum problems let you query ranges. This one makes you build the prefix sum yourself by choosing order. It's a step up: you're optimizing the sequence, not just computing it.
Is 41% acceptance rate the same across all companies?+
Acceptance rates vary by company OA pool and question variants, but 41% overall suggests this isn't a gimme. Candidates who skip the greedy pattern and brute-force often fail or TLE. Clear understanding of the trick is the gap.
Want the actual problem statement? View "Rearrange Array to Maximize Prefix Score" on LeetCode →